I hate this girl but she thinks we’re friends

I’ve known this girl (who let’s just call Kate) for a solid year now, and we only met because my friends knew her, and soon she started hanging around where we ate at school as well. She is a talented artist and mostly just talks about her original characters and their stories or whatever, and as an artist myself I thought I would enjoy her company then. But no, it’s really quite the opposite. She’s constantly talking about her characters even if no one asked, and even worse, she’s always asking specifically ME if I would ‘smash’ her characters or whatever. Even when I try to escape the question sooner by giving an answer I don’t mean, she’ll then ask me AGAIN who’d I wanna fuck instead. It’s just gross. It gets worse though. We shared a study hall all year, and I don’t know about you, but I prefer my study hall being alone and taking the time to catch up on any unfinished work from the day so I don’t have any when I arrive home. But it doesn’t matter, because every chance she gets she’s trying to talk to me about her characters, show me some humorless picture on her phone, or distract me from my work. And I don’t usually say anything to spare her feelings, but when I do, I usually sound like I’m the jerk. Disgustingly enough, most of her characters have disturbing backstories of one similar theme. About 3-4 characters she’s described to me in brutal detail have been sexually assaulted. Once, I was doing my work in study hall, and Kate asked if she could share with me her character. I said sure, but then she gave me a warning and said it’s pretty intense. I thought she meant it was violent, so I said she could just text me instead. But no. She declined my offer to text it and instead told me she wanted to tell the story personally. She then went on to describe in sickening detail, bit by bit, how her fictional 12 year-old girl OC was, well… you know- by her stepfather. Kate didn’t think once to whisper either, despite being in a dead silenced classroom for study hall. I didn’t even realize where things were heading until she described how the girl would wake up day after day with her underwear and pants off, and not remember a thing. She even fucking smiled at me when she said her stepfather was never caught. And the fact that this isn’t the first character she has had this happen to either makes me think maybe it’s a fetish to her. Even worse, it’s probably her kink to tell it to people how they’re, you know. I could go on and on and on about every other weird element about her, but at the end of the day I hate her guts more than anyone I’ve ever met. For some reason she thinks we’re friends. She texts me random pictures I guess I’m supposed to find funny, and tells me about how (just yesterday) her friend will call drawings of my characters hot or whatever, and say that they want to fuck them. Then she happily reports this back to me like I’m supposed to be celebrating? I’m not a fucking sexualizing creep like you are, Kate, for the love of god, do not sexualize my characters. It’s gotten to the point where I’ve had dreams about beating her up, she’s just to intolerable, but I don’t have the heart to tell her off when she seems so oblivious to her own delusions. I can’t help but hate her, yet other people seem to enjoy her company, so what’s different here?